The Effect of Crack Orientation on Ethanol-Induced Crack Healing in Poly (Methyl Methacrylate)

Jin-Shin Ho; Ching-Bin Lin; Zue-Chin Chang

doi:10.6180/jase.2008.11.1.02

The Effect of Crack Orientation on Ethanol-Induced Crack Healing in Poly (Methyl Methacrylate)

Jin-Shin Ho¹ , Ching-Bin Lin This email address is being protected from spambots. You need JavaScript enabled to view it.¹ and Zue-Chin Chang²

¹Department of Mechanical & Electro-mechanical Engineering, Tamkang University, Tamsui, Taiwan 251, R.O.C.
²Department of Mechanical Engineering National Chin-Yi Institute of Technology, Taiping City, Taichung County, Taiwan, R.O.C.

Received: December 18, 2006
Accepted: April 10, 2007
Publication Date: March 1, 2008

Download Citation: ||https://doi.org/10.6180/jase.2008.11.1.02

ABSTRACT

The line- and the cross-crack healing of Poly(methyl methacrylate) (PMMA) under the ethanol treatment at 40 ºC ~ 60 ºC have been studied. The cross-crack means that the crack plane is vertical to the crack plane of the line-crack. The effective glass transition temperature of PMMA is reduced after the ethanol treatment. Both crack healings only occur at the effective glass transition temperature lower than the transport temperature. Both crack closure rates are constant. The closure rate of the cross-crack is higher than that of the line-crack. The analyses of the surface morphology and mechanical strength show that there are also two stages for crack healing which is wetting and diffusion. The tensile fracture stress of the healed specimen increases with a rise in volume fraction of the absorbing ethanol. The tensile fracture stress of healed PMMA with cross-crack only can be recovered to the virgin material. The tensile fracture stress of healed PMMA with cross-crack is larger than that with the line-crack.

Keywords: Line- and Cross-Crack Healing, Poly (Methyl Methacrylate), Ethanol

REFERENCES

[1] Lin, C. B., Lee, S. and Liu, K. S., “Methanol-Induced Crack Healing in Poly(methyl methacrylate),” Polym. Eng. Sci., Vol. 30, p. 1399 (1990).
[2] Wang, P. P., Lee, S. and Harmon, J. P., “Ethanol-Induced Crack Healing in Poly(methyl methacrylate),” J Polym Sci. Part B: Polym. Phys., Vol. 32, p. 1217 (1994).
[3] Jud, K. and Kaush, H. H., “Load Transfer through Chain Molecules after Interpenetration at Interfaces,” Polymer Bulletin, Vol. 1, p. 697 (1979).
[4] Wool, R. P. and O’Connor, K. M., “A Theory Crack Healing in Polymers,” J. Appl. Phys., Vol. 52, p. 5953 (1981).
[5] Kim, Y. H. and Wool, R. P., “A Theory of Healing at a Polymer-Polymer Interface,” Macromolecules, Vol. 16, p. 115 (1983).
[6] Skewis, J. D., “Self-Diffusion Coefficients and Track of Some Rubbery Polymers,” Rubber Chem. Technol., Vol. 39, p. 217 (1966).
[7] Wool, R. P., “Relation for Healing, Fracture, Self-Diffusion and Fatigue of Random Coil Polymers,” ACS Polym. Prepr., Vol. 23, p. 62 (1982).
[8] Voyutskii, S. S., Autoadhesion and Adhesion of Polymers, in: Polymer Rev., Vol. 4, Wiley-Interscience, New York (1963).
[9] Wool, R. P., Polymer interface: structure and strength. New York: Hanser (1995).
[10] Wool, R. P. and O’Connor, K. M., “Crazing Healing in Polymer Glasses,” Polym. Eng. Sci., Vol. 21, p. 970 (1981).
[11] Harmon, J. P., Lee, S. and Li, J. C. M., “Methanol Transport in PMMA: The Effect of Mechanical Deformation,” J. Polym. Sci.: Part A: Polym. Chem., Vol. 25, p. 3215 (1987).
[12] Harmon, J. P., Lee, S. and Li, J. C. M., “Anisotropic Methanol Transport in PMMA after Mechanical Deformation,” Polymer, Vol. 29, p. 221 (1988).
[13] Yu, C. C., Lin, C. B. and Lee, S., “Theory for the Rate of Crack Closure,” J. Appl. Phys, Vol. 78, p. 212 (1995).
[14] Jud, K., Kausch, H. H. and Williams, J. G., “Fracture Mechanics Studies of Crack Healing and Welding of Polymers,” J. Mater. Sci., Vol. 16, p. 204 (1981).
[15] Beuchem, F., Physical Properties of Polymers, Ch. 5. Robert F. Krieger Publishing Co., New York (1979).